mercury 75 hp cooling

[toddy2pints]

75 hp 1986 4 cylinder been stood for a couple of years,started on the button but no water from pee hole. Replaced impeller blew through hole,then decided to take off head cover plate(really wished i hadnt 9 of the twelve bolts sheared)got the last gasket in the uk and refitted still no better!! Then removed exhaust cover and plate stripped and cleaned and blew air into waterways refitted and still nothing.The only way i seem to be able to cool the engine is with a hose connected to the water intake tube with the lower unit removed.With the lower unit fitted it will pump water but intermitantly, and the water feels pretty hot. Any advice on what to do next would be much appreciated!!

 

[Coloradolakeboy]

Re: mercury 75 hp cooling

For more help, post up what you have done so far. It's best to include the serial number. I did not completely understand your post, so I am guessing that everyone else here did not as well... since there where no replies.
Although we all speak english here, we may have a terminology problem.

 

[Fed]

Re: mercury 75 hp cooling

If you're testing it in a container remember the pump is not self priming and the pump is way higher than the intake grill so you really need to submerge it properly.
Are you sure you got the little key in the impeller properly?

 

[toddy2pints]

Re: mercury 75 hp cooling

Thanks for the replies,have now put lower unit back on and tested,the only way i can get the engine to cool properly is to leave the bleed screw in the head cover plate loose,after maybe 20 seconds the telltale starts to work with a good steady stream of water and then lock of the bleed screw and ran the engine for maybe 10 mins. Engine seemed to cool fine head cover cool,exhaust cover cool tell,tale stream warm but no steam and water coming from exhaust holes on leg,stopped engine left for 10 mins tried again without undoing bleed screw, no water from telltale but water muffs really getting sucked against intake. and no water coming from anywere, any ideas anyone?

 

[Fed]

Re: mercury 75 hp cooling

Open up your tap, there should be water spewing out of the sides of the muffs.

 

[toddy2pints]

Re: mercury 75 hp cooling

Thanks Fed all sorted now ran the engine in a waterbutt tonight, instant cooling from telltale loads of water from exhaust ports on leg. Seems maybe the damned hose was the problem all along!! Going to clean the carbs tomorrow and hopefully get out for a ski on Sunday, many thanks!!